Moar doc

Document the use of GIT_ASKPASS and SSH_ASKPASS.

BUG=
R=dpranke@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=211148

[Dirk Pranke, 2013-07-10 00:54:25]

lgtm, but make the CL subject / description actually say something useful before
landing :).

https://codereview.chromium.org/18851004/diff/1/gclient_scm.py
File gclient_scm.py (right):

https://codereview.chromium.org/18851004/diff/1/gclient_scm.py#newcode1040
gclient_scm.py:1040: # message produced by git will be copied to gclient's
output.
nit: this doesn't mention why we need to set SSH_ASKPASS also. Is that needed? 

You could also delete "That shouldn't happen in the chromium workflow, and if it
does, then" without losing much.

[commit-bot: I haz the power, 2013-07-10 01:01:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/szager@chromium.org/18851004/1

[M-A Ruel, 2013-07-10 01:02:50]

https://codereview.chromium.org/18851004/diff/1/gclient_scm.py
File gclient_scm.py (right):

https://codereview.chromium.org/18851004/diff/1/gclient_scm.py#newcode1041
gclient_scm.py:1041: env = kwargs.get('env') or kwargs.setdefault('env',
os.environ.copy())
In general I'd recommend:
env = kwargs.setdefault('env', os.environ.copy())

In practice the code you wrote saves a dict copy but it's python, so we prefer
readability over performance in general.

[commit-bot: I haz the power, 2013-07-10 01:03:25]

List of reviewers changed. maruel@chromium.org did a drive-by without LGTM'ing!

[szager1, 2013-07-11 17:39:00]

Committed patchset #1 manually as r211148.